On matchday 1, there are 2 match highlights that are definitely interesting for me to look forward to, namely Milan vs Newcastle and PSG vs Dortmund.
Regarding history and teams performance right now in their domestic leagues, I find AC Milan better than Newcastle and PSG better than Dortmund. I might say Newcastle United might pick a draw in their away match but I doubt Dortmund could do the same, the best they can in that case is to try to keep goal difference as low as possible.
Meanwhile, on matchday 2 I am interested in watching Madrid vs Union Berlin, Arsenal vs PSV, Bayern Munich vs Manchester United, and Sevilla vs Lens.
Real Madrid is better than Union Berlin and should win that match. Arsenal could do it as well.
For Sevilla and Lens, both are doing horribly in their leagues and I fail to think which one will play miserably than the others..
With quite an entertaining schedule between all the games I'm looking forward to Bayern Munich's debut against Man United.
This game is quite hard to calculate. Bayern Munich is okay while Manchester United isn't that stable right now. Everything could happen, I think Bayern Munich will win but I wouldn't be surprised with a draw too.